DUMP(5)             UNIX Programmer's Manual		  DUMP(5)



NAME
     dump, ddate - incremental dump format

SYNOPSIS
     #include <sys/types.h>
     #include <sys/ino.h>
     #include <dumprestor.h>

DESCRIPTION
     Tapes used by _d_u_m_p and _r_e_s_t_o_r(8) contain:

	  a header record
	  two groups of bit map records
	  a group of records describing directories
	  a group of records describing files

     The format of the header record and of the first record of
     each description as given in the include file <_d_u_m_p_r_e_s_t_o_r._h>
     is:

     #if  UCB_NKB == 1
     #define NTREC    10
     #endif
     #ifndef	      UCB_NKB
     #define NTREC    20
     #endif
     #define MLEN     16
     #define MSIZ     4096

     #define TS_TAPE  1
     #define TS_INODE 2
     #define TS_BITS  3
     #define TS_ADDR  4
     #define TS_END   5
     #define TS_CLRI  6
     #define MAGIC    (int)60011
     #define CHECKSUM (int)84446
     struct	      spcl
     {
	  int	      c_type;
	  time_t      c_date;
	  time_t      c_ddate;
	  int	      c_volume;
	  daddr_t     c_tapea;
	  ino_t       c_inumber;
	  int	      c_magic;
	  int	      c_checksum;
	  struct      dinodec_dinode;
	  int	      c_count;
	  char	      c_addr[BSIZE];
     } spcl;




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DUMP(5)             UNIX Programmer's Manual		  DUMP(5)



     struct	      idates
     {
	  char	      id_name[16];
	  char	      id_incno;
	  time_t      id_ddate;
     };

     _N_T_R_E_C is the number of BSIZE (sys/param.h) byte records in a
     physical tape block.  _M_L_E_N is the number of bits in a bit
     map word.	_M_S_I_Z is the number of bit map words.

     The _T_S_ entries are used in the _c__t_y_p_e field to indicate
     what sort of header this is.  The types and their meanings
     are as follows:

     TS_TAPE Tape volume label
     TS_INODE
	     A file or directory follows.  The _c__d_i_n_o_d_e field is
	     a copy of the disk inode and contains bits telling
	     what sort of file this is.
     TS_BITS A bit map follows.  This bit map has a one bit for
	     each inode that was dumped.
     TS_ADDR A subrecord of a file description.  See _c__a_d_d_r
	     below.
     TS_END  End of tape record.
     TS_CLRI A bit map follows.  This bit map contains a zero bit
	     for all inodes that were empty on the file system
	     when dumped.
     MAGIC   All header records have this number in _c__m_a_g_i_c.
     CHECKSUM
	     Header records checksum to this value.

     The fields of the header structure are as follows:

     c_type   The type of the header.
     c_date   The date the dump was taken.
     c_ddate  The date the file system was dumped from.
     c_volume The current volume number of the dump.
     c_tapea  The current number of this (512-byte) record.
     c_inumber
	      The number of the inode being dumped if this is of
	      type _T_S__I_N_O_D_E.
     c_magic  This contains the value _M_A_G_I_C above, truncated as
	      needed.
     c_checksum
	      This contains whatever value is needed to make the
	      record sum to _C_H_E_C_K_S_U_M.
     c_dinode This is a copy of the inode as it appears on the
	      file system; see _f_i_l_s_y_s(5).
     c_count  The count of characters in _c__a_d_d_r.
     c_addr   An array of characters describing the blocks of the
	      dumped file.  A character is zero if the block



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DUMP(5)             UNIX Programmer's Manual		  DUMP(5)



	      associated with that character was not present on
	      the file system, otherwise the character is non-
	      zero.  If the block was not present on the file
	      system, no block was dumped; the block will be
	      restored as a hole in the file.  If there is not
	      sufficient space in this record to describe all of
	      the blocks in a file, _T_S__A_D_D_R records will be scat-
	      tered through the file, each one picking up where
	      the last left off.

     Each volume except the last ends with a tapemark (read as an
     end of file).  The last volume ends with a _T_S__E_N_D record and
     then the tapemark.

     The structure _i_d_a_t_e_s describes an entry of the file
     /_e_t_c/_d_d_a_t_e where dump history is kept.  The fields of the
     structure are:

     id_name  The dumped file system is `/dev/_i_d__n_a_m'.
     id_incno The level number of the dump tape; see _d_u_m_p(8).
     id_ddate The date of the incremental dump in system format
	      see _t_y_p_e_s(5).

FILES
     /etc/ddate

SEE ALSO
     filsys(5), types(5), dump(8), dumpdir(8), restor(8)



























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